CVE-2024-38821 in Spring Security
Summary
by MITRE • 10/28/2024
Spring WebFlux applications that have Spring Security authorization rules on static resources can be bypassed under certain circumstances.
For this to impact an application, all of the following must be true:
* It must be a WebFlux application * It must be using Spring's static resources support * It must have a non-permitAll authorization rule applied to the static resources support
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Analysis
by VulDB Data Team • 11/06/2024
Spring WebFlux applications utilizing Spring Security for authorization enforcement face a critical vulnerability that allows bypass of access controls for static resources under specific conditions. This vulnerability stems from a flaw in how Spring Security evaluates authorization rules when applied to static resource endpoints within reactive web applications. The technical implementation fails to properly validate authentication state when processing requests for static content, creating a pathway for unauthorized access that directly contradicts the intended security posture.
The vulnerability operates through a specific interaction between Spring WebFlux's reactive request handling and Spring Security's authorization mechanisms. When static resources are configured with authorization rules that exclude permitAll access, the security framework does not consistently enforce these restrictions across all request pathways. This inconsistency arises from the asynchronous nature of WebFlux applications where the security context may not be properly propagated or validated during static resource processing. The flaw creates an authorization bypass condition that can be exploited by malicious actors to access protected static content without proper authentication.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data exposure and privilege escalation risks. Attackers can leverage this bypass to access sensitive static resources such as configuration files, documentation, or other protected assets that should only be available to authenticated users. The vulnerability affects the fundamental security model of WebFlux applications and can result in information disclosure, system compromise, or compliance violations depending on the nature of the static content. Organizations running Spring WebFlux applications with static resource authorization rules face significant risk of unauthorized data access and potential system infiltration.
Security professionals should implement immediate mitigations including updating to patched versions of Spring Framework and Spring Security components, reviewing all static resource authorization rules, and conducting comprehensive security assessments of reactive web applications. The vulnerability aligns with CWE-285, which addresses improper authorization in software systems, and maps to ATT&CK technique T1078.004 for valid accounts and T1566.001 for spearphishing attachments, as attackers may exploit this bypass to gain access to sensitive static resources. Organizations should also consider implementing additional monitoring and logging controls to detect unauthorized access attempts and ensure proper authorization enforcement across all application components.